Which has a bigger cup — Giardinelli Sym. T or Kelly 12C?

The Giardinelli Sym. T has a cup diameter of 25.80 mm / 1.0157 in compared to 24.13 mm / 0.9500 in on the Kelly 12C — a difference of 1.67 mm / 0.0657 in. A wider cup generally produces a fuller, darker tone but requires more air support.

How does cup depth compare between Giardinelli Sym. T and Kelly 12C?

The Giardinelli Sym. T has a deep cup while the Kelly 12C has a shallow cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.

Giardinelli Sym. T vs Kelly 12C

Name: Kelly 12C
Brand: Kelly

The Giardinelli Sym. T has a wider cup diameter, the Giardinelli Sym. T features a deeper cup.

Overall Comparison Cup Diameter Cup Depth Rim Width Throat Diameter Backbore Finish Material

The width of the rim surface that contacts the lips. Wider rims improve endurance; narrower rims improve flexibility.

Mouthpiece A

Giardinelli Sym. T

• Trombone

Rim width—

Best suited for

🎻Orchestral playing — large cup for full, dark tone

📣High-volume projection — open throat for power

Mouthpiece B

Kelly 12C

• Trombone

Lead

Rim width—

Best suited for

📋Lead trombone; smallest cup

Which is better?

Neither mouthpiece clearly dominates the other — the right choice depends on your embouchure, playing style, and the sound you're after. Try both if possible.

Open in interactive tool + Add third mouthpiece Giardinelli Sym. T details Kelly 12C details Giardinelli Sym. T equivalents Kelly 12C equivalents

Giardinelli Sym. T vs Kelly 12C

Playing Characteristics

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What Changes If You Switch?

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